In certain types of underground metal ore mining it is common to break up the rock face by drilling and blasting. The rubble or broken ore is then removed by a mucking operation. Usually the necessary operations are intermittent and successive. For example, blasting holes are drilled, the drilling machine is moved out, explosive handlers come in to place charges in the holes and detonate them and then a loader or other loading and/or transporting machine is brought in to gather and/or pick up the rubble or broken ore and move it away from the mining face. This type of mining is slow and awkward and greatly limits the productive capacity of the men and machines.
There have recently been developed high blow energy hydraulic hammers or impactors adapted for impact breaking of rock from the solid. One of these hydraulic impactors is shown in U.S. Pat. No. 4,089,380 which shows a machine in which kinetic energy of a reciprocating piston is transferred to the tool through a hydraulic coupling. (See also companion U.S. Pat. Nos. 4,062,268 and 4,012,909). Compared to other machines, these impact hammers, while sufficiently light and compact to be mounted on a hydraulic boom universally mounted so that it can direct the breaking force of the tool over substantially the whole of the face being mined, provide sufficient blow energy to break rock from the solid and therefore permit a non-cyclic, uninterrupted mining operation.
By employing high blow energy impactors on a movable machine with provision for mucking, continuous mining in hard rock can be accomplished.